The present invention relates to an articulated vehicle, more particularly, to an articulated vehicle which can enhance the operation capability over severe terrain that the ground is rough and winding and reduce fuel consumption. References to “the invention” herein should be understood to be references to one or more aspects of the invention.
Construction vehicles as construction equipments have been developed in various shapes to satisfy various demands for providing necessary functions at the work site under various environmental conditions and for effectively displaying individual functions even in severe conditions.
As a representative example of such construction vehicles, there are vehicles being operated while loaded. Such vehicles are generally classified into an articulated dump truck and a rigid dump truck.
An articulated dump truck refers to a vehicle wherein the vehicle body for accommodating the load is connected by a plurality of modules. A rigid dump truck refers to a vehicle in the shape of a body. Specifically, the present invention relates to an articulated vehicle. Such an articulated vehicle is basically operated in a normal condition. When an articulated vehicle is operated in severe conditions, however, there would be many difficulties in operation itself. Particularly, in the event an articulated vehicle is operated in the area that the terrain is seriously curved or the ground is not firm, there would be substantial difficulties in operating the articulated vehicle due to many variables. Below is an example of such case:
When the wheels of an articulated vehicle pass over the ground that is neither flat nor firm or is severely curved and rough, the center of gravity of the vehicle may be moved considerably toward one side. Thus, it would be difficult to keep its balance. In a worse case, it may lead to vehicle overturn. A repetitive operation in such terrain will cause a problem, such as giving a shock to a driver. Accordingly, safety and terrainability of a vehicle will be considerably lowered.
In addition, under this situation, several wheels of the vehicle body fail to be in sufficient contact with the ground, and thus they cannot display their traction force or will be spinning with no traction, which may result in difficulty in operation. In order to solve these problems, a leveling arrangement may be used. The leveling arrangement prevents the center of gravity of a vehicle from leaning rapidly toward one side on the ground that is not flat to secure stability of the vehicle. Specifically, the leveling arrangement regulates the height of the axle connected to each of the right and left wheels so that the vehicle maintains level.
However, if a vehicle is equipped with the leveling arrangement, the manufacturing costs will considerably increase. Moreover, it is not easy to control the leveling arrangement, and it is not guaranteed that a vehicle equipped only with the leveling arrangement will be stably operated. Accordingly, when an articulated vehicle is operated, it is important to prepare a measure for reduction in fuel consumption, as well as smooth steering or maintenance of vehicle stability. Normal articulated vehicles are configured such that each wheel is connected to an axle fixed on the vehicle body to travel on the rotational axis of the axle, and vehicle bodies are adjacently connected without relative rotation.
In the articulated vehicles, in which such a type of wheel is formed, when each vehicle travels straight ahead, the wheels of the following vehicle are operated according to the route of the wheels of the preceding vehicle. Thus, the wheels are not dragging. However, when traveling on a severely curved or rough ground, each of the wheels of the connected vehicles rolls toward the traveling direction and creates traction on its own. Thus, at least one vehicle wheel is dragging. Since such dragging considerably increases fuel consumption, a measure for solving this problem is required. Furthermore, when an articulated vehicle is operated on a severe curve, adjacently connected vehicle bodies are merely dragged without relative rotation and steering. Thus, operation capability of the articulated vehicle is significantly lowered. In a worse case, the vehicle is broken away or turned over.
Also, if a customer would have an application that sometimes requires a large conventional articulated vehicle, but mostly only a smaller one, this customer would either have to buy two sets of vehicles in the right size (but this costs a lot of money) or they would buy only one, large vehicle, which most of the time would be over-sized and thus not energy-efficient.
The present invention was designed to solve the aforesaid problems. The present invention provides an articulated vehicle, wherein, even if each wheel connected to a plurality of vehicles is individually suspended without having a steering function, rotation or steering of each vehicle body and the route of each vehicle wheel are selectively controlled to minimize fuel consumption and enhance traction force.
An articulated vehicle according to a preferred example of the present invention comprises:
a first vehicle body;
a first pair of wheels, which are individually suspended on both sides of the first vehicle body and can travel on the ground;
a second vehicle body, which is hingedly connected to the first vehicle body;
a second pair of wheels, which are individually suspended on both sides of the second vehicle body and can travel on the ground;
a regulator, which regulates the relative steering angle between the first vehicle body and the second vehicle body;
a mode selector, which selects a first mode and a second mode; and
a controller, which receives the first mode signal or the second mode signal from the mode selector and controls the regulator according to the received signal,
wherein the route of a second pair of wheels is regulated to be identical to the route of a first pair of wheels in the first mode; and the route of a second pair of wheels is regulated to be different from the route of a first pair of wheels in the second mode.
As another characteristic feature, the present invention provides an articulated vehicle comprising a drive unit, which individually drives a first pair of wheels and a second pair of wheels; and a transmission, which changes the speed of a first pair of wheels and the speed of a second pair of wheels.
And as another characteristic feature, the present invention provides an articulated vehicle, wherein the distance from the hinge to the first pair of wheels is equal to the distance from the hinge to the second pair of wheels.
And as another characteristic feature, the present invention provides an articulated vehicle, wherein the regulator regulates a first pair of wheels and a second pair of wheels to be linearly arranged without rotating the first vehicle body and the second vehicle body in the first mode.
And as another characteristic feature, the present invention provides an articulated vehicle, wherein the regulator regulates the steering angle between the first vehicle body and the second vehicle body so that the first wheels and the second wheels are arranged on a curve which forms a concentric circle with the vehicle center route in the first mode.
And as another characteristic feature, the present invention provides an articulated vehicle, wherein the route of the second wheels to repeatedly cross the route of the first wheels in the second mode.
And as another characteristic feature, the present invention provides an articulated vehicle, wherein the second vehicle body is regulated to repeat a clockwise rotation and a counterclockwise rotation on the basis of the first vehicle body.
An articulated vehicle according to another example of the present invention comprises:
a third vehicle body hingedly connected to the second vehicle body and a third pair of wheels, which are individually suspended on both sides of the third vehicle body and can travel on the ground, wherein the regulator regulates the relative steering angle between the first vehicle body and the second vehicle body and the relative steering angle between the second vehicle body and the third vehicle body;
the route of a third pair of wheels is regulated to be identical to the route of a first pair of wheels and a second pair of wheels in the first mode; and
the route of a third pair of wheels is regulated to be different from the route of a first pair of wheels and a second pair of wheels in the second mode
An articulated vehicle according to another example of the present invention comprises a drive unit, which individually drives a first pair of wheels, a second pair of wheels, and a third pair of wheels and a transmission, which changes the speed of a first pair of wheels, a second pair of wheels and a third pair of wheels.
According to an example of the present invention as stated above, modes vary depending on terrain or operation conditions. Specifically, in the first mode, each wheel route of adjacently connected vehicle bodies is regulated to be identical to minimize rolling frictions of the wheels of the following vehicle, which results in reducing fuel consumption. In the second mode, the wheel route of the preceding vehicle and the wheel route of the following vehicle are regulated to be different to increase traction force of the wheel of the following vehicle body, which allows easy operation of an articulated vehicle. That is, the articulated vehicle of the present invention achieves both a lower fuel consumption and easy operation.
Further, the present invention controls rotation and steering of mutually adjacent vehicle bodies, which enhances the operation capability and stability over severe terrain.
Further, unlike the conventional articulated vehicle, wherein the load is being taken by the vehicle body frame, which makes a design to counteract bending and torsional stresses necessary, which in turn results in increasing the vehicle weight and fuel consumption, the vehicle in the present invention is designed such that the load is mostly supported directly above the wheels, which makes a lighter frame design possible and due to decreased total mass results in an advantage of reducing fuel consumption.